refactor: move from io/ioutil to io and os package

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

connector/atlassiancrowd/atlassiancrowd_test.go

@@ -6,7 +6,7 @@ import (
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
@@ -152,7 +152,7 @@ func newTestCrowdConnector(baseURL string) crowdConnector {
 	connector := crowdConnector{}
 	connector.BaseURL = baseURL
 	connector.logger = &logrus.Logger{
-		Out:       ioutil.Discard,
+		Out:       io.Discard,
 		Level:     logrus.DebugLevel,
 		Formatter: &logrus.TextFormatter{DisableColors: true},
 	}